LOS ANGELES — Dogs and cats have become part of the American family's inner circle over the past 20 years, sleeping in their own beds or yours, eating food bought specially to help their digestive tracts, drinking purified water and cuddling up in chairs on heated pads made to fend off arthritis.

In addition to veterinarians, some pets have their own groomers, trainers, sitters and occasional walkers.

All this suggests a bright future for an industry that has grown with the popularity of pets, expanding at a steady 4 to 6 percent a year since the American Pet Products Association started record-keeping in 1996.

Americans spent an all-time high $55.7 billion on their pets last year, and spending will inch close to $60 billion this year, association president and CEO Bob Vetere told buyers and exhibitors at the Global Pet Expo in Orlando on Thursday.

The biggest chunk of 2013 spending, $21.6 billion, went for food — a lot of it more expensive, healthier grub. In 1996, total pet spending was just $21 billion. Adjusted for inflation, that's $31.3 billion.

The humanization of our pets started about 20 years ago, Vetere said. As pets accepted their new perch in the family, manufacturers introduced products that helped animals move from the backyard to the front room.

"What is feeding a large part of the growth now are the baby boomers who have become empty-nesters and are looking for some other ways to find the love and affection they used to get from their kids," Vetere said.

Dave Bolen is president and CEO of Pet Supplies Plus, a chain of 294 specialty stores in 24 eastern states. His 25-year-old business has expanded every year — it opened eight stores in 2013 and Bolen plans to open 30 more this year.

"We are bullish about pet ownership," he said.

Other spending last year included $14.4 billion for veterinary care; $13.1 billion for supplies and over-the-counter medicines; and $4.4 billion for other services. Those services include grooming, boarding, training and pet-sitting and grew by the largest percentage last year, at 6.1 percent.

American pets include an estimated 95.6 million cats and 83.3 million dogs, the APPA said.